The financial fraud group that is investigating the market for residential mortgage-backed securities has already issued civil subpoenas to 11 financial institutions, Attorney General Eric Holder Jr. said Friday in formally announcing the team of lawyers and federal agents.

Holder and top Obama administration officials, speaking Friday with reporters at the Justice Department, declined to discuss the details of the pending investigations. The focus of the group is on the organization and securitization of home loans, not loan servicing.